SOMO-14D work for the gruvin9x board

src/gruvin9x/somo14d.cpp

@@ -150,9 +150,14 @@ ISR(TIMER4_COMPA_vect) //Every 0.5ms
     return BUSY;
 }
 
-void somoPushPrompt(uint16_t prompt)
+void pushPrompt(uint16_t prompt)
 {
   somo14playlist[somo14WIdx] = prompt;
   somo14WIdx = (somo14WIdx + 1) % QUEUE_LENGTH;
   TIMSK4 |= (1<<OCIE4A);
 }
+
+bool isPlaying()
+{
+  return TIMSK4 & (1<<OCIE4A);
+}

src/gruvin9x/somo14d.h

@@ -31,4 +31,8 @@
  *
  */
 
-extern void somoPushPrompt(uint16_t prompt);
+#define PROMPT_CUSTOM_BASE 100
+
+extern void pushPrompt(uint16_t prompt);
+extern bool isPlaying();
+